Sunday, December 8, 2013

Rudimentary Radio Tales

This is another excerpt from Screen Saver.  The wires again lead inevitably to a blinding flash.

“Wires coming out the back of radios” was a recurring theme of my early memories. Usually they also involved some sort of catastrophe.

There was the transistor radio I built. I had experienced, starting not long after the atomic attack several entertaining, educational and even successful encounters with various versions of the famous old time crystal set. I had also experienced one highly unsuccessful, and expensive, attempt to follow the directions in some “Popular, Something or Other” magazine for building a one transistor radio.

One of the components from the failed one transistor radio project took me to the pinnacle of crystal set building. That component was an extremely low voltage variable capacitor. If you had ever ripped open an old time radio, or had one smashed to the floor before your very eyes, you would have recalled seeing a thing that looked like a pair of interleaving three quarter (one quarter was missing) metal circles. Coming out of the center of the circles would have been a shaft and prior to ripping open or decomposing the radio you would have found a knob on that shaft on the front panel of the radio. This was the tuning device.

The one from my failed one transistor radio had looked exactly like the one described, including a little shaft for a knob. But it wasn’t possible to see the circles of interleaving plates; they were beautifully enclosed in a case of thin white plastic. And rather than being the size of a carton of butter it had been more the size of four quarters piled on top of one another. Of course the case was square. Once the one transistor project had been declared a complete failure I had disposed of most of the components, but I hadn’t been able to bear to dispose of that beautiful little variable capacitor, although I had no earthly use for it.

So I continued working with my crystal sets. The crystal set was how I became a rock and roll fan. On my set I was able to get several stations. This was before cheap or even affordable transistor radios, so kids didn’t usually have real radios. My crystal set had filled that void.

The important station I that could get was KPOJ. Starting at 8 or 9 in the evening a local disk jockey named Dick Novak opened “The Rhythm Room” for all of us, mostly kids out there listening. The broadcast was a remote from Amato’s Supper Club, a Portland attempt at a nightclub. He played songs, and people who were at Amato’s for dinner, drinks and the show came to talk to him and the whole thing was magical; or so it had seemed to me. So the crystal set had become my closest friend. I was still in transition to humanity.

Friend though it might have been, the crystal set had disadvantages: weak signal exacerbated by inexact tuning. The tuning mechanism on a crystal set was a tuning coil. To make a tuning coil you saved an empty toilet paper core and shellacked it several times to give it durability and rigidity. That shellacked tube also provided an ideal non-electronic base for the rest of the device, which was very thin bare copper wire. The wire was wound in neat sequential, non overlapping turns, and then shellacked and let dry. Then a second coat was applied and let dry and then a track was carefully sanded in the shellacked wire to bare copper across the length of the tube. It was this bare copper track that, when engaged by a rotating metal arm that accomplished tuning on a crystal set. The only problem was that the rotating arm was a broad contact point to the tuning coil’s thin copper wire. That fact didn’t matter a whole lot because the crystal providing the signal was a pretty weak and inexact input source. But one could dream of improvement. And there had been some improvements. I had read somewhere that soldering a wire to the underside of the tuning arm would improve selectivity; and it did. But it still was far from ideal. One could still dream.

In the back of my mind had been for some time the question: “what if I could use the low voltage variable capacitor? Without a battery would the device even work?” There wasn’t anything on a crystal set that could use a battery. Whatever current that existed was the signal from the crystal. “Was whatever current that came off the crystal sufficient to drive the variable capacitor?” I had continued to ponder.

I had disposed of “most” of the parts for the failed transistor project. In addition to the variable capacitor I had also saved the germanium diode. The crystal on a classical crystal set was called a cat’s whisker. A cat’s whisker had two components that were joined on a substrate with connectors so the device could be put into the crystal set’s circuit. One component was a chunk of germanium which senses radio waves. That chunk of germanium was imbedded in a round slug of lead, or solder. The other component was a little arm with a knob on one end and a coil of spring wire with an extending snout – the cat’s whisker. This arm was mounted in a vertical stanchion, which was mounted on the substrate. This arrangement allowed for the variable positioning, rotating right and left and up and down with the “whisker” searching for a sensitive spot in the crystal. It was pretty sophisticated mechanically, but not much from an electronic viewpoint.

I had an intellectual grasp of the merits of the germanium diode over the cat’s whisker. The diode consisted of highly refined germanium enclosed in a little tube sealed and reinforced at either end by a metal seal and with an access wire coming out of each end. When the thing was hooked into the device it was intended for it provided a maximum, constant, non-variable signal. It was the tuner’s job to sort that signal out. Even though I knew those advantages it had never occurred to me to substitute the diode for the cat’s whisker.

Until one day it did occur to me. I removed the cat’s whisker and replaced it with the diode. And it worked. So now I had a great source of signal, with really sloppy tuning. It was obviously the time to see if the low volt variable capacitor would work. Now the problem arose, how do I attach it – not physically, but logically? For some reason I felt I needed to retain the tuning coil, but add the variable capacitor; but I wasn’t quite sure how to do it. I decided that putting the capacitor in series with the coil made sense. So I did that, shoved the capacitor in one end of the tube, which made for a perfectly snug mount for the capacitor, and – it worked. It was unbelievable. I could rough tune with the coil and then get several stations from that position with the capacitor. I felt as if I had invented radio.

Then I found in some magazine that I read – probably Boys Life – that I could buy a “kit” for a one transistor radio. It looked to have significant advantages over my previous attempt: the price was way less, all components were included, it was small, to be placed after being assembled on a small substrate into a neat little pillbox of clear plastic that snapped positively closed; and there was a minimum of soldering. The previous project had failed in part due to my lack of soldering skills. I had cooked my nine-dollar transistor. Nine dollars had been a lot of money to try to replace in those days, especially for a kid.

So I sent for the kit. And it went together beautifully. And it worked like a real radio, even better than my souped up crystal set. But I was never one to be satisfied with the status quo. So I was constantly gilding the lily. The radio worked with an antenna only; it didn’t need a ground. A ground is an iron rod pounded into the ground. An even better ground is a cold water pipe. My crystal set had always used a ground, which was always a hassle, so no ground was a good thing. All I needed to work on improving was the antenna. Was there any way to improve the signal being presented to the diode?

I had at this time an electric alarm clock that had been reduced to bare guts, so many times had it been knocked on the floor when attempting to wake me. It still worked fine, though, and I didn’t care that it was a clock face mounted in the frontal remains of what had previously been a case, with most of its workings exposed. Those workings included the two screws that attached the dual strands of electrical cord to the clock. That dual bolt exposure proved to be serendipitous. Somehow, I had discovered that bringing the antenna in proximity to those electric terminals improved the antenna unbelievably. I found that attaching the antenna to one of the terminals with an alligator clip was even better, and certainly more permanent. So I lived happily with my enhanced antenna for some time. But I had a question in the back of my mind. Would a ground even improve things more? There was a perfectly serviceable cold water pipe in the yard right outside my window.

So I wrapped some copper wire tightly around the water pipe, having dropped it down from my window and went back to my room and attached the ground to the radio. As with the encounter with the cat’s cradle, the immediate results of this action contributed some of my clearest and most intense of memories: “how could I be so stupid?”

The room lit up with a flash. It filled with a melted plastic smell. Tendrils of smoke floated ceiling-ward from the two electrical terminals on the clock whose hands were frozen in time and space at 5:33. The little pool of melted plastic next to it had only a few seconds before been my one transistor radio. I always had a special place in my heart for that little radio.

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